PDCD1 and urinary bladder cancer: A previous study pointed out that strong response to immunotherapy in non-small-cell lung cancer patients is related to high APOBEC signatures,25 and another reported high PD-1 expression in hypermutated bladder cancer tumours with APOBEC signatures.33 Therefore, the high immunogenicity of the IR type may be related to the high APOBEC activity in the tumour cells.